I wasn't sure which section to post this.

I've heard the term for this is hovering hands?

Has anyone reached out to touch your shoulder or arm. Maybe to comfort or reassure you. Instead of making contact, they hover their hand just above briefly and bring their arm down to their side.

Is the person not usually touchy feely and this is their attempt or way of comforting? Testing the waters to see if the other person looks comfortable and next time make contact? Or something else?

The person doing the hovering could be someone you met before once or several times. Not a total stranger.